1. Field of the Invention
The present invention is related to a data checking technique, and more particularly, to an apparatus for checking data coherence, a redundant array of independent disks (RAID) controller and a storage system having the same, and a method therefor.
2. Description of Related Art
During data transmission, errors always occur in the transmitted data due to whatever reasons. For a receiving end, the data become unreliable after being transmitted. For example, when data are transmitted in a communication environment on the Internet, such as through Internet small computer system interface (iSCSI), the transmitted data usually have errors therein. Hence, there are various error detection methods or apparatuses used to solve this problem in the present, in which cycle redundancy check (CRC) codes are used most often. If the errors can be detected, through the CRC codes, for example, the receiving end can request the transmission end to send the data again, and the transmitted data can be protected thereby.
While data in transmission can be protected through the above-mentioned technologies, data stored in a memory device may be protected by redundant data (or check data) corresponding thereto. For example, the data stored in a RAID (Redundant Array of Independent Disks) data storage architecture may have check data with it. While data stored may have check data with it for protecting its coherence, there could be the situation that the data read from memory devices such as from disk drives, including the regular data and its check data, is not coherent to each other for whatever reasons.
Accordingly, to provide an apparatus and method for checking data coherence is an urgent need to fulfill.